KR20040094737A - Vane type vacuum pump - Google Patents

Abstract

A vane type vacuum pump having a rotor that rotates while sliding the ben in contact with the housing is provided with at least one set of circular annular shapes which are provided concentrically with the rotation shaft between the housing and the rotor and are fitted to be movable relative to each other in the circumferential direction. It is provided with a labyrinth-shaped thread covering almost every circumference having a groove and a circular annular protrusion. The protrusions or grooves provided in the casing may be continuous, but the circular protrusions or grooves are continuous on the casing side, but the reliefs are provided as discontinuities so as not to interfere with the radial movement of the ben on the rotor side.

Description

Vane vacuum pump {VANE TYPE VACUUM PUMP}

The conventional vane vacuum pump shown in cross section in FIGS. 12 and 13 has a housing 1, which has a cup-shaped body 3 having a suction port 2 and a discharge port 4 with a valve. ) And a bracket 6 which closes the open end of the main body 3 and forms the pump chamber 5 therein. The pump chamber 5 is a cylindrical space formed by two end faces 7 and 8 parallel to each other of the housing 1, and a cylindrical face 9 between the end faces 7 and 8. The bearing shaft 10 of the bracket 6 is supported by the bearing shaft 12 of the inner end main body 3 of the rotary shaft 11 by being eccentrically supported with respect to the central shaft center of the cylindrical pump chamber 5. have. Pinions, pulleys, sprockets, cams, and the like 13 which receive the driving force from a drive device (not shown) such as an external gear are fixed to the outer end of the rotary shaft 11.

In the housing 1, a rotor 14 concentrically with respect to the rotation shaft 11 and thus eccentric with respect to the pump chamber 5 (housing 1) is housed. The rotor 14 is a substantially cylindrical member having two cross sections and a cylindrical surface, and is rotated in the housing 1 by the rotation shaft 11. The rotor 14 is provided with four slots 15 extending from the end face to the end face in the radial direction through the shaft center, and each of the slots 15 slides in contact with the cylindrical surface 9 of the housing 1 at the distal end thereof. Ben 16 which can be fitted is slidably fitted in the radial direction.

In such a vane vacuum pump for a vehicle, when the rotor 14 is rotated clockwise in FIG. 11, the ben 16 in the slot 15 moves outward by centrifugal force, and the tip of the ben 16 is in the pump chamber. It slides in contact with the cylindrical surface 9 of (5). Since the rotating shaft 11 of the rotor 14 is eccentric with respect to the center of the pump chamber 5, the volume of the compression chamber formed between the bens 16 changes with the rotation of the rotor 14, and the housing Air is sucked in from the inlet port 2 of (1) and pumped to the outlet port 4 to generate a vacuum on the inlet port 2 side connected to a tank (not shown). At this time, the various sliding parts in the vane vacuum pump, in particular, the parts in which the ben 16 slides in contact with other parts such as the rotor 14, the end faces 7 and 8 of the housing 1, and the cylindrical surface 9, etc. In addition, the bearing portion is supplied with engine oil from the outside, and their sliding contact portions are lubricated.

The side sections 7 and 8 of the housing 1 and the axial end face of the rotor 14 are also sliding portions, between which an oil film of engine oil is interposed to prevent both wear and the rotor. The airtight between the and the housing is secured. However, the oil film fracture may occur locally in the sliding portion between them. When the oil film breakage occurs, not only the problem of abrasion occurs, but the effect of the airtight retention is lowered, and there is a problem that the vacuum characteristic of the vane type vacuum pump is lowered.

In order to solve such a problem, the capacity of the pump may be increased or the rotor rotation speed may be increased. However, in the former, the vane type vacuum pump has an increased external dimension, so that the mounting to the engine is deteriorated and the weight is increased. In the latter case, problems such as an increase in vibration, a decrease in life due to an increase in mechanical wear, and the like arise.

The present invention relates to a vane type vacuum pump, and more particularly to a vane type vacuum pump for vacuuming a tank used for a vehicle.

1 is a schematic cross-sectional view showing a vane type vacuum pump according to a first embodiment of the present invention along line 1-1 of FIG.

FIG. 2 is a schematic sectional view in axial vertical plane of the vane vacuum pump of FIG. 1. FIG.

3 is a schematic cross-sectional view showing details of a maze-shaped seal of the vane vacuum pump of FIG. 1;

Figure 4 is a partial perspective view of the rotor and the van of the present invention.

5 is a schematic cross-sectional view showing a vane type vacuum pump according to a second embodiment of the present invention.

6 is a schematic cross-sectional view showing details of a labyrinth-shaped seal of the vane vacuum pump of FIG. 5.

Figure 7 is a partial perspective view of the rotor and the van of the present invention.

8 is a schematic cross-sectional view showing a vane type vacuum pump according to a third embodiment of the present invention.

9 is a schematic cross-sectional view showing a vane type vacuum pump according to a fourth embodiment of the present invention.

10 is a schematic cross-sectional view showing an example in which the vane vacuum pump of FIG. 4 is directly connected to an alternator.

11 is a graph showing the results of comparative tests of the degree of vacuum of the vane type vacuum pump of the present invention shown in FIGS. 1 to 4 and the conventional vane type vacuum pump shown in FIGS. 12 and 13.

12 is a schematic cross-sectional view of a conventional vane vacuum pump taken along line 12-12 of FIG.

FIG. 13 is a schematic sectional view in axial vertical plane of the vane vacuum pump of FIG. 12; FIG.

It is therefore an object of the present invention to provide a small vane type vacuum pump having high airtightness between the rotor and the housing, good vacuum characteristics, sufficient lubrication and low wear.

The configuration of the vane vacuum pump of the present invention for achieving this object is as follows.

(1) a housing having a cylindrical pump chamber having an inlet and an outlet, a rotor eccentrically housed in the pump chamber, a rotating shaft fixed to the rotor and rotating the rotor in the pump chamber, and the rotor while slidingly contacting the housing in the pump chamber. A vane-type vacuum pump having a ben fitted in a radial direction and freely entering and exiting in a radial direction, forcing air in the pump chamber from the inlet to the outlet by rotating the rotor, thereby generating a vacuum on the inlet side, between the housing and the rotor. A labyrinth-shaped seal that is provided concentrically with the axis of rotation and has at least one set of circular annular grooves and circular annular protrusions fitted relative to one another in a circumferential direction. A vane vacuum pump comprising: a.

(2) A circular annular protrusion may be provided in the cross section of the rotor, and a circular annular groove may be provided in the rotor.

(3) Even if a circular annular groove is provided in the side cross-section of the rotor, a circular annular protrusion is provided in the rotor, and a recess is provided in the side cross-section of the ben so as not to interfere with the radial movement of the ben. good.

(4) A plurality of sets of labyrinth-like threads may be provided in concentric circles.

(5) Maze-shaped threads may be provided on both side cross-sections of the rotor.

(6) The rotating shaft may be an output rotating shaft of the vehicle alternator.

The vane vacuum pump of the present invention shown in FIGS. 1 to 3 has a housing 21, which has a cup-shaped body 23 having a suction port 22 and a discharge port 24 with valves. ) And a bracket 26 for closing the open end of the main body 23 to form the pump chamber 25 therein. The pump chamber 25 is a cylindrical space formed by two cross sections 27 and 28 parallel to each other of the housing 21 and a cylindrical surface 29 between the cross sections 27 and 28. The bearing shaft 30 of the bracket 26 is supported by a rotation shaft 31 disposed through the cylindrical pump chamber 25, and the inner end of the rotation shaft 31 is supported by the bearing 32 of the main body 23. have. The rotary shaft 31 is disposed eccentrically with respect to the central axis of the pump chamber 205. Pinions, pulleys, sprockets, cams, and the like 33 which receive transmission of driving force from a drive device (not shown) such as an external gear are fixed to the outer end of the rotary shaft 31.

In the housing 21, a rotor 34 concentrically with respect to the rotation shaft 31 and thus eccentric with respect to the pump chamber 25 (housing 21) is housed. The rotor 34 is a substantially cylindrical member having two flat sections 35 and 36 and a cylindrical surface 37, which is rotated in the housing 21 by the rotation shaft 31. The rotor 34 is provided with four slots 38 extending in the radial direction from the end face to the end face through the shaft center. In this slot 38, the tip 39 can slide in contact with the cylindrical surface 29 of the housing 21, respectively, and the flat end faces 40 and 41 have end faces 27 and 28 of the housing 21, respectively. The plate-shaped ben 42 which slide-contacts is provided in this, and it is possible to slide in the radial direction in the slot 38. As shown in FIG.

As best shown in Figs. 3 and 4, in the end faces 35 and 36 of the rotor 34, an annular protrusion concentric with the rotation shaft 31, except for the position where the slot 38 is formed, 43 is provided. The end faces 35 and 36 of the housing 21 are provided with a continuous annular groove 44 which is provided at a position corresponding to the annular protrusion 43 and receives the protrusion 43. The radial gap 45 and the axial gap 46 between the groove 44 and the protrusion 43 are both end faces 35 and 36 of the rotor 34 and end faces of the housing 21. It is larger than the gap between (27, 28), and the axial gap 46 is larger than the gap 45 in the radial direction. For this reason, a space for storing engine oil is formed between the annular protrusion 43 and the annular groove 44. Moreover, since this space is formed between the protrusion 43 and the groove 44, the space of the labyrinth shape which obstructs the movement of engine oil in the radial direction is comprised.

When the rotor 34 is rotated counterclockwise in FIG. 2, the ben 42 moves radially outward by the centrifugal force in the slot 38, and the tip 39 of the ben 42 moves to the pump chamber 25. It slides in contact with the cylindrical surface 29 of. Since the rotating shaft 31 of the rotor 34 is eccentric with respect to the center of the pump chamber 25, the volume of the compression chamber formed between the ben 42 changes with the rotation of the rotor 34, and the housing Air is sucked in from the inlet port 22 of 21 and pumped to the outlet port 24 to generate a vacuum on the inlet port 22 side connected to a tank (not shown).

At this time, various sliding parts in the vane vacuum pump, in particular, the ben 42 slide-contacts to other parts such as the rotor 34, the end faces 27 and 28 of the housing 1, and the cylindrical surface 29, Further, engine oil is supplied from the outside to the bearing portion, and their sliding contact portions are lubricated.

According to the present invention, in the sliding portion between the side end faces 27 and 28 of the housing 1 and the axial end faces 35 and 36 of the rotor 34, an annular concentric shape with the rotation shaft 31 is formed. The protrusion 43 and the continuous ring-shaped groove 44 which receives the protrusion 43 are provided, and the maze-shaped thread bent in a U shape between the groove 44 and the protrusion 43 is provided. And a space for storing the engine oil at the same time. Therefore, the labyrinth-shaped seal prevents the engine oil from flowing out from the slide portion and destroys the oil film, and also allows the engine oil to be continuously supplied from the storage space, thereby preventing wear between the slide movement portions. With this, airtightness between the rotor and the housing is ensured.

5-7, the annular protrusion 47 is provided in the side wall 27 and 28 of the housing 21, and the annular groove 48 is provided in the end surface 35 and 36 of the rotor 34. In FIG. An example is shown. The projection 47 on the housing 21 side is an annular projection having a substantially rectangular cross section concentric with the rotation shaft 31 of the rotor 34. The groove 48 provided in the rotor 34 is an annular projection concentric with the rotating shaft 31 that receives the protrusion 47, but is partially cut at the portion of the slot 38 that houses the ben 42. In the end face 40 of the ben 42, the ben 42 can slide in the radial direction with respect to the rotor 34 in the slot 38 without interfering with the protrusion 47 on the housing 21 side, The recessed part 49 as a relief groove is provided.

Also in this vane type vacuum pump, the sliding part between the side end surfaces 27 and 28 of the housing 1 and the axial end surfaces 35 and 36 of the rotor 34 is located on the housing 21 side. An annular protrusion 47 and an annular groove 48 for receiving the protrusion 47 on the rotor 34 side are provided, and between the groove 48 and the protrusion 47 is U-shaped. A curved labyrinth-shaped thread is formed, and at the same time, a space for storing engine oil is formed. Therefore, while preventing abrasion between the sliding parts, airtightness between the rotor and the housing is ensured.

In the vane type vacuum pump shown in FIG. 8, the double annular protrusions 51 and 52 are provided in the cross section of the rotor 34, and the double annular grooves 53 and 54 are provided in the housing 21 side. . Each of the protrusions 51 and 52 and the grooves 53 and 54 is of the same structure as shown in Figs. In this vane type vacuum pump, since the labyrinth-shaped thread and the oil storage space are doubled, the seal effect is significantly improved as compared with the previous embodiment.

In the vane type vacuum pump shown in FIG. 9, the double annular grooves 55 and 56 are provided in the cross section of the rotor 34, and the double annular protrusions 57 and 58 are provided in the housing 21 side. . Each of the grooves 55 and 56 and the protrusions 57 and 58 is of the same structure as shown in Figs. The relief grooves 59 provided in the end faces 47 and 48 of the ben 42 are large enough in radial direction so as not to interfere with the double protrusions 55 and 56 and the grooves 57 and 58. In this vane type vacuum pump, the labyrinth-shaped seal and the oil storage space are doubled, and the seal effect is greatly improved.

10 is a schematic cross-sectional view showing an example in which the vane vacuum pump shown in FIGS. 1 to 4 is directly connected to a vehicle alternator. In the illustrated example, the vehicle alternator 60 is a rotor having a rotating shaft 65 supported by a stator 62 supported in the housing 61 and bearings 63 and 64 attached to the housing 61. The electron 66 is provided, and in the drawing of the rotation shaft 65, the left end extends out of the housing 61 and enters into the housing 71 of the vane type vacuum pump 70 of the present invention. That is, the bracket 72 of the housing 71 of the vane type vacuum pump 70 is attached to the housing 61 of the vehicle alternator 60, and this bracket 72 does not have a bearing, but the housing main body 73 is attached. Is attached to constitute a housing 71 of the pump. The rotor 34 of the vane type vacuum pump 70 is attached to the rotating shaft 65 in the housing 71, and the circular ring-shaped protrusion 43 according to the present invention is located between the rotor 34 and the housing 71. ) And a circular annular groove 44 are provided, and a labyrinth-shaped thread is formed over almost every circumference.

FIG. 11 is a graph showing the results of comparative tests on the degree of vacuum between the vane type vacuum pump of the present invention shown in FIGS. 1 to 4 and the conventional vane type vacuum pump shown in FIGS. 12 and 13. The two curves (A and B) of the graph show the change of the vacuum when the suction side of the vane type vacuum pump is expressed by the height of the mercury column (mmHg) with respect to the change in the operating time (seconds) on the horizontal axis. , Curve A represents the vacuum characteristics of the vane type vacuum pump of the present invention, and curve B represents the vacuum characteristics of a conventional vane type vacuum pump. From this graph, the difference in vacuum degree gradually increases from the start of the pump to the normal operation state, and in the constant speed operation state, the vacuum degree itself becomes the normal state, and in the case of the present invention, the vacuum degree is about 12% to about 15%. I can understand the increase.

As is apparent from the above description, the vane type vacuum pump of the present invention is provided concentrically with the rotation shaft 31 between the housing 21 and the rotor 34, and can be moved relative to each other in the circumferential direction (that is, rotatable). It is provided with a labyrinth-shaped thread covering almost every circumference having at least one set of annular protrusions 43 and 47 and circularly annular grooves 44 and 48 fitted together.

A circular annular protrusion 43 may be provided in the cross section of the rotor 34, a circular annular groove 44 may be provided in the housing 21, and the circular annular groove 48 is the rotor 34. Is provided on the side end face of the circular annular protrusion 47 in the housing 21, and the protrusion 47 of the housing 21 is received on the side end face of the ben 42 to receive the diameter of the ben 42. A concave portion 49 may be provided so as not to disturb the directional motion. In addition, a plurality of sets of labyrinth-shaped threads may be provided in concentric circles, or labyrinth-shaped threads may be provided on both side cross-sections of the rotor.

As mentioned above, the vane type vacuum pump which concerns on this invention is especially useful as a vacuum pump for making the inside of the tank which comprised the braking power booster of a vehicle into a vacuum.

Claims (6)

A housing having a cylindrical pump chamber having an inlet and an outlet; A rotor eccentrically housed in the pump chamber, A rotating shaft fixed to the rotor and rotating the rotor in the pump chamber; A ben fitted in the rotor while slidingly contacting the housing in the pump chamber, the ben having a free entry and exit in a radial direction, In the vane type vacuum pump which rotates the said rotor, the air in the said pump chamber is pumped from the said suction port to the said discharge port, and a vacuum is generated in the said suction port side, A labyrinth shape that is provided concentrically with the rotational shaft between the housing and the rotor and has almost a circumference having at least one set of circular annular grooves and circular annular protrusions fitted to be movable relative to each other in a circumferential direction; A vane vacuum pump comprising a seal. The method of claim 1, The circular annular projection is provided in the cross section of the rotor, the circular annular groove is provided in the rotor, characterized in that the vane vacuum pump. The method of claim 1, The circular annular groove is provided in the side end surface of the rotor, the circular annular protrusion is provided in the rotor, and the concave portion receiving the protrusion in the side end surface of the ben so as not to interfere with the radial motion of the ben. A vane vacuum pump, characterized in that provided. The method according to any one of claims 1 to 3, A plurality of sets of the labyrinth-shaped yarns are provided in concentric circles. The method according to any one of claims 1 to 3, The labyrinth-type vacuum pump, characterized in that the labyrinth-shaped seal is provided on both side cross-sections of the rotor. The method according to any one of claims 1 to 3, The vane vacuum pump, characterized in that the rotary shaft is the output rotary shaft of the vehicle alternator.